stall the plane, note the speed
[...]
then take the speed you noted as stalling, multiply it by 1.3 and you now have vref on a nice day with steady wind.
This is not a good idea. The way you describe it, you will do the calculation using IAS, but you must use CAS.
If you take the C172S the OP is flying, at gross weight it will stall at 40 kt IAS (assuming the POH data is correct). 40*1.3 = 52. 52 kt IAS is about 57 kt CAS. But the CAS at stall is 48-50 kt (depending on power). Assume 49. 49*1.3 ≈ 64. So you will end up with a Vref about 7 kt too slow!
(Not incidentally, 64 kt CAS corresponds to 61 kt IAS, which is exactly the Vref figure given in the POH.)